package com.zhaohg.security;

import org.apache.commons.codec.binary.Hex;
import org.bouncycastle.crypto.digests.MD5Digest;
import org.bouncycastle.crypto.macs.HMac;
import org.bouncycastle.crypto.params.KeyParameter;

import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

public class HMACUtil {
    private static String src = "zhaohg security hmac";

    public static void main(String[] args) {
        jdkHmacMD5();
        bcHmacMD5();
    }

    public static void jdkHmacMD5() {
        try {
            KeyGenerator keyGenerator = KeyGenerator.getInstance("HmacMD5");//初始化KeyGenerator
            SecretKey secretKey = keyGenerator.generateKey();//产生密钥
//			byte[] key = secretKey.getEncoded();//获得密钥
            byte[] key = Hex.decodeHex(new char[]{'a', 'a', 'a', 'a', 'a', 'a', 'a', 'a', 'a', 'a'});

            SecretKey restoreSecretKey = new SecretKeySpec(key, "HmacMD5");//还原密钥
            Mac mac = Mac.getInstance(restoreSecretKey.getAlgorithm());//实例化MAC
            mac.init(restoreSecretKey);//初始化Mac
            byte[] hmacMD5Bytes = mac.doFinal(src.getBytes());//执行摘要
            System.out.println("jdk hmacMD5 : " + Hex.encodeHexString(hmacMD5Bytes));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void bcHmacMD5() {
        HMac hmac = new HMac(new MD5Digest());
        hmac.init(new KeyParameter(org.bouncycastle.util.encoders.Hex.decode("aaaaaaaaaa")));
        hmac.update(src.getBytes(), 0, src.getBytes().length);

        byte[] hmacMD5Bytes = new byte[hmac.getMacSize()];//执行摘要
        hmac.doFinal(hmacMD5Bytes, 0);

        System.out.println("bc hmacMD5 : " + org.bouncycastle.util.encoders.Hex.toHexString(hmacMD5Bytes));

    }
}
